You will need three applications. All can be installed directly from Google Play. None of them modify game data. Two of them are just widgets (those placed on the Android desktop), and the other is an app that converts widgets to overlay.

You will do the entire setup directly in the Overlays app. Just go into it, and click on the red icon to add a widget. Make this process for each widget, and place them to activate with the FFBE application.
In the Overlay app configuration. For the threshold widget, disable the option to click on it. Already for the counter widget, leave the option to click on it enabled.